xref: /xnu-10002.81.5/osfmk/man/host_get_clock_control.html (revision 5e3eaea39dcf651e66cb99ba7d70e32cc4a99587)
1*5e3eaea3SApple OSS Distributions<h2>host_get_clock_control</h2>
2*5e3eaea3SApple OSS Distributions<hr>
3*5e3eaea3SApple OSS Distributions<p>
4*5e3eaea3SApple OSS Distributions<strong>Function</strong> - Return a send right to a kernel clock's control port.
5*5e3eaea3SApple OSS Distributions<h3>SYNOPSIS</h3>
6*5e3eaea3SApple OSS Distributions<pre>
7*5e3eaea3SApple OSS Distributions<strong>kern_return_t   host_get_clock_control</strong>
8*5e3eaea3SApple OSS Distributions                <strong>(host_priv_t</strong>                          <var>host_priv</var>,
9*5e3eaea3SApple OSS Distributions                 <strong>clock_id_t</strong>                                  <var>id</var>,
10*5e3eaea3SApple OSS Distributions                 <strong>clock_ctrl_t</strong>                     <var>clock_control</var><strong>);</strong>
11*5e3eaea3SApple OSS Distributions</pre>
12*5e3eaea3SApple OSS Distributions<h3>PARAMETERS</h3>
13*5e3eaea3SApple OSS Distributions<dl>
14*5e3eaea3SApple OSS Distributions<p>
15*5e3eaea3SApple OSS Distributions<dt> <var>host_priv</var>
16*5e3eaea3SApple OSS Distributions<dd>
17*5e3eaea3SApple OSS Distributions[in host-control send right]
18*5e3eaea3SApple OSS DistributionsThe control port for the host owning the
19*5e3eaea3SApple OSS Distributionsclock.
20*5e3eaea3SApple OSS Distributions<p>
21*5e3eaea3SApple OSS Distributions<dt> <var>id</var>
22*5e3eaea3SApple OSS Distributions<dd>
23*5e3eaea3SApple OSS Distributions[in scalar]
24*5e3eaea3SApple OSS DistributionsThe identification of the desired kernel clock.  These values
25*5e3eaea3SApple OSS Distributionsare defined in \*L<mach/clock_types.h>\*O.  Although an implementation
26*5e3eaea3SApple OSS Distributionsmay define additional values, the following values are always defined
27*5e3eaea3SApple OSS Distributions(although only the REALTIME clock is required to be implemented):
28*5e3eaea3SApple OSS Distributions<dl>
29*5e3eaea3SApple OSS Distributions<p>
30*5e3eaea3SApple OSS Distributions<dt> <strong>REALTIME_CLOCK</strong>
31*5e3eaea3SApple OSS Distributions<dd>
32*5e3eaea3SApple OSS DistributionsA moderate resolution clock service that (typically) tracks
33*5e3eaea3SApple OSS Distributionstime since the system last boot.
34*5e3eaea3SApple OSS Distributions<p>
35*5e3eaea3SApple OSS Distributions<dt> <strong>BATTERY_CLOCK</strong>
36*5e3eaea3SApple OSS Distributions<dd>
37*5e3eaea3SApple OSS DistributionsA (typically) low resolution clock (to the second) that
38*5e3eaea3SApple OSS Distributionssurvives power failures or service outages.
39*5e3eaea3SApple OSS Distributions<p>
40*5e3eaea3SApple OSS Distributions<dt> <strong>HIGHRES_CLOCK</strong>
41*5e3eaea3SApple OSS Distributions<dd>
42*5e3eaea3SApple OSS DistributionsA high resolution clock.
43*5e3eaea3SApple OSS Distributions</dl>
44*5e3eaea3SApple OSS Distributions<p>
45*5e3eaea3SApple OSS Distributions<dt> <var>clock_control</var>
46*5e3eaea3SApple OSS Distributions<dd>
47*5e3eaea3SApple OSS Distributions[out clock-control send right]
48*5e3eaea3SApple OSS DistributionsControl port for the clock.
49*5e3eaea3SApple OSS Distributions</dl>
50*5e3eaea3SApple OSS Distributions<h3>DESCRIPTION</h3>
51*5e3eaea3SApple OSS Distributions<p>
52*5e3eaea3SApple OSS DistributionsThe <strong>host_get_clock_control</strong> function returns a send
53*5e3eaea3SApple OSS Distributionsright to the control port for
54*5e3eaea3SApple OSS Distributionsa kernel clock object.  This right is used to set the clock's
55*5e3eaea3SApple OSS Distributionsresolution and time.
56*5e3eaea3SApple OSS Distributions<h3>RETURN VALUES</h3>
57*5e3eaea3SApple OSS Distributions<p>
58*5e3eaea3SApple OSS DistributionsOnly generic errors apply.
59*5e3eaea3SApple OSS Distributions<h3>RELATED INFORMATION</h3>
60*5e3eaea3SApple OSS Distributions<p>
61*5e3eaea3SApple OSS DistributionsFunctions:
62*5e3eaea3SApple OSS Distributions<a href="clock_set_time.html"><strong>clock_set_time</strong></a>,
63*5e3eaea3SApple OSS Distributions<a href="clock_set_attributes.html"><strong>clock_set_attributes</strong></a>,
64*5e3eaea3SApple OSS Distributions<a href="host_get_clock_service.html"><strong>host_get_clock_service</strong></a>.
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